Laterally-driven piezoelectric bimorph MEMS actuator with sol-gel-based high-aspect-ratio PZT sturucture

This paper reports on the fabrication and characterization of a novel laterally-driven piezoelectric bimorph MEMS actuator with high aspect-ratio (AR) lead-zirconate-titanate (PZT) structure. In the fabrication process, the PZT structures (AR=8) was successfully fabricated by filling deep Si trenches with nanocomposite sol-gel PZT. A lateral displacement of 10 μm was obtained from a 500-μm-long actuator by bimorph actuation at driving voltages of +25 V/-5 V, while no vertical cross-motion as well as no initial vertical bending was observed. Compared with conventional capacitive comb-drive actuators, this actuator occupies a much smaller area to generate identical force or displacement. This actuator has the potential to become a new actuation technology in MEMS.